1. Technical Field
The present invention relates to exercise bicycles and more particularly to one configured to provide fan-based resistance and having a fan wheel whose hub and vanes are manufactured separately and then put together.
2. Description of Related Art
Conventionally, the resistance-providing fan wheel of a fan-based exercise bicycle includes a hub integrally formed with a plurality of vanes. As the hub and the vanes are integrally formed, the mold required is highly complicated and hence expensive.
To lower the costs of such molds, Taiwan Patent No. 386452, entitled “Improved fan wheel structure of exercise bicycle configured to provide fan-based resistance”, discloses symmetric enclosure portions and a plurality of vanes. The enclosure portions are wheel-like casings formed by stamping. The vanes are provided in the space between the enclosure portions and are soldered to the enclosure portions.
While the vanes in the afore-cited patent are fixed to the enclosure portions by soldering, it is well known in the art that soldering is disadvantageous in many ways. For example, a soldering technician is exposed to such risks as burns and inhalation of toxic gases, the high temperature of the soldering process may result in residual stresses, and a high level of craftsmanship is called for. Thus, the fan wheel structure in the afore-cited patent leaves something to be desired in terms of manufacture.